Sawdust collection apparatus for a table saw

ABSTRACT

Sawdust collection apparatus for a motorized table saw includes a specially formed and hinged, table top saw guard and sawdust collector to which one end of a vacuum hose is connected in a manner to admit air bleeding so as to safely lower the vacuum therein when the other end of the hose is connected to a relatively strong vacuum source, a deflector element to be mounted on the swinging saw cradle below the table in the saw base for directing sawdust downwardly to a collector bag, foamed synthetic material for sealing various openings in the saw base and a conveniently removable bracket for supporting the vacuum hose above the saw table.

This is a division of application Ser. No. 312,002, filed Oct. 16, 1981,now abandoned.

This invention concerns the provision of means for the collection of allsawdust produced in the operation of a motorized table saw and forpreventing the escape of sawdust from the saw table and base.

BACKGROUND OF THE INVENTION

Applicants have found that when attaching one end of a vacuum hose tothe usual hinged saw guard and the other end to a relatively strongvacuum source, such as a shop-vac, that small cut off work pieces werelikely to be picked up and sometimes drawn into the hose. This not onlycauses inconvenience it also presents a hazardous situation.

In a U.S. Pat. No. 4,367,655 for a sawdust collection system the jointinventors, Daniel A. Terpstra and Richard B. Brundage, of the presentapplication disclosed a sawdust collection system for a motorized tablesaw. This earlier disclosure included a flexible hose connected at oneend to a hinged saw guard and at its other end to a vacuum source ofknown capacity comprising a centrifugal blower connected to and drivenby an outboard mounted saw driving motor. In this case the capacity ofthe vacuum source to cause an airflow velocity through a hose of aspecific size was known to be low enough to avoid the pickup of smallwork pieces and it was stated that, "The capacity of the blower and thediameter of the connecting hose is such as to cause a relatively largevolume airflow through the saw guard at a relatively low rate of flow soas to collect virtually all of the fine sawdust likely to becomeairborne without withdrawing any appreciable amount of the largerheavier particles."

In the present invention applicants have provided a specially formedhinged saw guard having provision for the convenient detachableconnection thereto of a vacuum hose which permits a sufficient flow ofair into the hose from the exterior of the guard as well as from theinterior thereby to limit the velocity of airflow through the guard andpreclude the picking up of small cut off work pieces when an available,relatively strong vacuum is applied to the other end of the hose. Thisbleeding of exterior air into the vacuum hose not only reduces thevelocity of airflow through the guard to preclude the pickup of smallcut off work pieces it also induces the flow into the hose of finesawdust particles thrown alongside of the guard by the saw blade whenthe hinged guard is raised from the worktable by a workpiece.

Another problem encountered was the emission of sawdust from the sawbase through the sizeable arcuate aperture in the front wall of the baseprovided to permit the saw elevating screw, which passes therethrough,to swing with the tilting of the saw blade. In the earlier applicationreferred to herein above the applicants provided a strip of foamedmaterial enclosing this arcuate aperture. While this expedient iseffective in preventing the escape of sawdust through this aperture, anobjectionable amount yet escaped around the elevating screw due to theconsiderable velocity at which sawdust is thrown toward this aperture bythe saw blade. To effectively solve this problem applicants in thepresent invention have provided a U-shaped deflector tiltable with thesaw blade for directing all below table sawdust off the saw bladedownwardly into a collector bag attached to the open bottom of the base.

OBJECTS OF THE INVENTION

An object of this invention is to provide a hinged saw guard for a tablesaw which is formed so as to direct above table sawdust through arearward facing opening formed therein into the end of a vacuum hoseconnected thereto;

A further object is to provide the hinged saw guard with means forpositioning and for conveniently detachably connecting the end of thevacuum hose thereto;

A further object is to limit the vacuum applied through the vacuum hoseto the inside of the saw guard by bleeding air from outside the guardinto the connected end of the hose;

A further object is to provide deflector means movable with the sawblade in beveling positions for causing below table sawdust thrownforwardly by the saw blade to be directed downward into a collector bag;

A further object is to provide means for supporting a length of vacuumhose above the worktable which means may be conveniently moved out ofthe way when it interferes with sawing of a long workpiece;

A further object is to seal various openings in the casing forming thebase of a table saw with pieces of foamed material;

Further objects and advantages will appear from the followingdescription when read in connection with the accompanying drawings.

In the Drawings

FIGS. 1 and 2 are respectively side and front elevational views of amotorized table saw equipped with sawdust collection apparatusconstructed and applied thereto in accordance with the presentinvention;

FIGS. 3, 4 and 5 are enlarged fragmentary, detail views of the vacuumhose support bracket showing the means for mounting it on the rear ripfence rail;

FIG. 6 is an enlarged cross-sectional view of the table saw shown inFIGS. 1 and 2 with the legs deleted and is taken along line 6--6 of FIG.1;

FIG. 7 is an enlarged cross-sectional view of the table saw with thelegs deleted and is taken along line 7--7 of FIG. 2;

FIG. 8 is a still further enlarged fragmentary cross-sectional view ofthe sawdust deflector element and is taken along line 8--8 of FIG. 6;

FIG. 9 is a fragmentary cross-sectional view of the deflector elementshowing the method of connecting it to the cradle wall by clips, and istaken along line 9--9 of FIG. 7;

FIG. 10 is an enlarged side elevational view, with parts shown insection, of the hinged saw guard and attached vacuum hose;

FIG. 11 is a top plan view of the saw guard shown in FIG. 10 with thevacuum hose deleted but with the hose connector shown in detachablyconnected position;

FIG. 12 is an enlarged fragmentary, detail view showing the hoseattaching clip fixed to the saw guard for the detachable connection ofthe hose connector;

FIG. 13 is an enlarged fragmentary, detail view showing the clipattached to the saw guard for detachably connecting an intermediateportion of the vacuum hose to the saw guard, and

FIG. 14 is a cross-sectional view of the saw guard and vacuum hoseconnector and is taken along line 14--14 of FIG. 10.

DESCRIPTION OF A PREFERRED FORM OF THE INVENTION

Referring to the drawings, sawdust collection apparatus constructed inaccordance with the present invention is shown assembled on aconventional commercially available, motor driven table saw generallyindicated at 10. The table saw has a worktable 12 with front and rearsides and rip fence rails 14 extending along the front and rear sidesthereof and attached thereto. A base 16 below the worktable isrectangular in plan and forms a casing enclosing a saw driving motor 18having a drive shaft 19 to which is attached a circular saw blade 20. Apivoted saw cradle generally indicated at 22 on which the motor and sawblade are mounted for movement with the cradle in saw blade bevelingpositions and are pivotally mounted for saw blade elevating positions inwhich a peripheral portion of the saw blade is variably positioned abovethe worktable. The saw blade 20 is arranged to rotate counter clockwiseas viewed in FIG. 7, that is, with the upper and forward peripheralportions thereof moving forward and downward.

Referring to FIGS. 6 and 7 the cradle 22 has two opposite, parallel andvertical sidewalls 24 and 26, a front wall 28 and a top wall 30. The topwall 30 is attached to a horizontal rod 32 by integrally formed tabs 34and the rod 32 is in turn journalled for rotation in brackets 36 fixedto the saw table 12. The cradle 22 may therefore be swung left or rightto various saw bevel positions about the axis of rod 32 by rotation of abevel screw 38 engaged in a nut 40 pivotally mounted in the front wall28 of the cradle 22.

The motor 18 and the saw blade 20 attached to the motor drive shaft 19are mounted on a shaft 42 which is journalled in the opposite sidewalls24 and 26 of the cradle so that the motor and attached saw blade mayalso be rotated to various elevational positions by the rotation of anelevating screw 44 engaged in a nut 46 pivotally mounted in an extension17 of the motor frame. The arrangement is such that the saw blade 20 isparallel with, positioned adjacent and spaced outwardly from the cradlesidewall 26. The saw base 16 has opposite vertical sidewalls 48 and 50,vertical front and rear walls 52 and 54 and is open at the top andbottom. The upper and lower edge portions of the vertical base sidewallsand front and rear walls are formed horizontally and are overlapped andconnected by screw means (not shown). The upper overlapped edges of thebase walls are spaced downwardly from the saw table 12 and connectedthereto by screws 55.

The elevating screw 44, see FIG. 7, extends through the front wall 52 ofthe base and has a hand wheel 45 attached to the exterior end thereof.In order to permit arcuate movement of the screw 44 when the cradle istilted to various saw bevel positions an arcuate slot 56 is provided inthe front base wall 52. Inasmuch as below table sawdust is thrownforward toward the front wall of the saw base and the slot 56 thereinwith considerable force by the saw blade this becomes the major point ofsawdust leakage from the base. A sawdust collector bag 58 has its openend attached to the open base bottom. The open end of bag 58 isconnected to the skirt 59 of a leg set 60 for convenient detachment andreplacement preferably in a manner shown and described in FIGS. 17 to 19in U.S. Pat. No. 4,367,665 referred to above.

To prevent below table sawdust from being thrown forwardly by thesawblade toward slot 56 applicants have provided an L-shaped deflectorelement generally indicated at 62, which in conjunction with the cradlesidewall 26 to which it is attached, forms a U-shaped deflectorshrouding the downwardly moving peripheral portion of the rotating sawblade. The two parallel legs of this U-shaped deflector extendingparallel with and on opposite sides of the saw blade and with thevertically arranged, perpendicular connecting leg positioned outwardfrom a downwardly moving peripheral portion of said saw blade toeffectively deflect all below table sawdust off the saw blade downwardlyinto the collector bag 58. The deflector element 62 is preferably formedas a molding of relatively rigid synthetic plastic and is of general Lshape having a short leg 64 and a long leg 66. The short leg 64 liesperpendicular to and coextends vertically with the cradle sidewall 26and has its edge abutting this cradle wall. The long leg 66 is parallelto cradle wall 26 and coextends vertically and horizontally rearwardtherewith. The deflector legs 64 and 66 also extend downward below thelower edge of cradle sidewall 26. The short deflector leg 64 is of suchlength that it spaces the longer leg 66 outwardly from cradle wall 26substantially twice the distance that the saw blade is spaced fromcradle wall 26.

At its upper end deflector 62 is provided with detached and outwardlyformed integral clip elements 68 on both legs which coextend verticallywith upper end portions of the legs 64 and 66. A sheet of easilydeformable material 70 such as foamed rubber has its lower edge portionretained between upper end portions of legs 64 and 66 and clip elements68 whereby the sheet 70 conforms to the L shape of the deflectorelement. The sheet 70 extends upwardly from the legs 64 and 66 ofdeflector 62 to the under side of the saw table 12 and provides aneasily deformable upward extension of the deflector 62 which permitstilting of the cradle.

The deflector 62 is also provided with an integral connector leg 72which extends perpendicularly from the edge of short leg 64 and liesflat against the cradle sidewall 26. A thickened portion 73 at theforward end of connector leg 72 provides a shoulder 74 which liesagainst the forward edge of wall 26 and thereby locates the position ofthe deflector horizontally. The lower edge of connector leg 72 isaligned with the lower edge of cradle sidewall 26 and a pair of springclip elements 76 hold the connector leg 72 and the edge of shortdeflector leg 64 firmly against the cradle wall 26, see FIGS. 7 and 9.The clip elements 76 are located by insertion in slight depressions 77in the face of leg 72.

To effectively collect the mostly fine sawdust which is thrown upwardand forward above the worktable by the saw blade applicants haveprovided a uniquely formed hinged saw guard generally indicated at 78arranged for the positioning and convenient detachable connection of theend of a rearward extending flexible vacuum hose to a forward endportion thereof. The forward end portion of the guard being formed so asto direct sawdust rearwardly through a rearward facing opening into thevacuum hose and so as to admit sufficient air to flow into the vacuumhose from outside the guard to avoid the pickup of small cut off workpieces. Referring to FIGS. 10 and 11 the horizontally disposed elongatedsaw guard 78 normally rests on worktable 12 and has rear and forwardends and is preferably formed as a molding of rigid, transparent,synthetic plastic material. The guard 78 has two spaced parallel,longitudinally extending vertical sidewalls 80 with their lowerhorizontal edges normally resting on worktable 12 and joined at theirupper edges by a horizontal top wall 82 and at their forward edges by aninclined front end wall 84. End wall 84 extends from bottom to top edgesof vertical sidewalls 80 and diverges forwardly from the bottom edge atan acute angle to the vertical. The guard 78 is open at its rear end andis pivotally connected intermediately of its length at 86 to an arm 88which in turn is pivotally connected rearwardly of the guard at 90 to aspreader 92. The spreader 92 is connected to the rotatable rod 32 (in amanner not shown) so as to tilt to various bevel positions with the sawblade.

The horizontal top wall 82 extends forward from the rear end of theguard to a forward end 83 which forward end is spaced rearward from thefront end wall 84. Near its forward end the top wall 82 is provided withlongitudinally extending and longitudinally spaced, depressions 94 and96. Depressions 94 and 96 are arranged to fittingly receive theintermediate flange 99 and forward end portion 98 of a conventional,commercially available, relatively rigid, hollow cylindrical hoseconnector generally indicated at 101. The bottom of longitudinallyextending depression 96 is arcuate with its axis on a line whichdiverges upward and rearward from the horizontal at an acute angle andthe axis of the hollow cylindrical hose connector 101 coincides withthis axis when the forward end portion 98 thereof is resting in arcuatedepression 96. The bottom of depression 94 extends laterally straightacross the top wall 82 and receives the flange 94 and is substantiallythe axial length of flange 99 whereby the connector 101 is axiallylocated.

The vertical sidewalls 80 have upwardly extending forward end portions100 which converge upward and have top edges which converge rearward andare connected by a top wall portion 102. The sidewall portions 100 andconnecting top wall portion 102 extend rearward from the top of frontend wall 84 to the forward end of arcuate depression 96. The rearwardconverging top edges of sidewall portions 100 and connecting top wallportion 102 extend rearward from the top of front end wall 84 atapproximately the same angle as the axis of connector 101 when itsportion 98 rests in depression 96 and the rear edges of sidewallportions 100 are vertical. Rear end portions of sidewall portions 100and top wall 102 enter the forward end portion 98 of hose connector 101due to its inclined position. The forward end portion 98 of theconnector 101 is of such diameter and wall thickness that the narrowedrear end portion of top wall 102 lies contiguous with an upper innerwall portion thereof when a lower diametrically opposed, exterior wallportion thereof is resting in arcuate depression 96. A spring clip 104firmly attached to the rear end of top wall portion 102, as by crimping,see FIG. 12, receives and holds the hose connector 101 in position withits axis approximately parallel to top wall 102.

The side and top wall portions 100 and 102 form an upper passageway atthe forward end of the saw guard with a rearward facing opening throughwhich above worktable sawdust off the saw blade is caused to flow intothe hose connector 101 by airflow created by rotation of the saw bladein the absence of a source of vacuum. The spacing of sidewall portions100 and their upward convergence permits ample air from the exterior ofthe guard to flow into hose connector 101 when a vacuum is applied to ahose connected to the hose connector thereby considerably reducing thevacuum applied to the interior of the saw guard. Cutouts 105 in the rearends of sidewall portions 100 may be varied in size to admit more orless bleeding of exterior air into hose connector 101. The upperconvergence of sidewall portions 100 and the rearward convergence oftheir upper edges results in a narrow rear end portion of top wallportion 102 rendering it adaptable to the entering and connection to thewall of portion 98 of hose connector 101.

The hose connector 101 has a rear threaded portion 106 for theattachment thereto of one end of a flexible, spirally convoluted vacuumhose 108. From the connector 101 the hose 108 extends rearward along thetop wall 82 of the guard and is fastened thereto. A strap 110 encirclingthe hose 108 and a spring clip 112 fixed to the top wall 82 near itsrear end retains the strap 110 and provides a convenient detachableconnection of the hose 108 to the top wall 82. From this connection thehose 108 extends horizontally and upwardly along the rear side of thesaw table to the semi-circular formed upper end of a wire hose supportbracket generally indicated at 114.

Referring to FIGS. 2 to 5 the support bracket 114 has a generallyhorizontal portion 115 terminating at its left end in a loop or eye 116.The eye 116 is mounted for rotation on a rubber bushing 118 fastened tothe rear rip fence rail 14 by a bolt 120 and is held in position onbushing 118 by a pair of washers 122. Near its right end the portion 115rests on a similar rubber bushing 124 connected to the rail 14 by a bolt126 and is held in position on bushing 124 by a pair of washers 122. Atthe right end of portion 115 the bracket is formed generallyperpendicular and extends vertically from portion 115 and terminates atits upper end in a semi-circular portion 128 for receiving hose 108 andsupporting it well above the saw table. When it becomes necessary tolower the hose support bracket 114 and move the hose out of the way toavoid interference with an unusually long workpiece to be sawed theright end of bracket portion 115 is merely lifted from its seat onbushing 124 and lowered.

Referring to FIGS. 6 and 7, the spaces between the upper horizontallyformed and overlapped edges of the side, front and rear walls of the sawbase and the underside of the saw table are closed by strips of foamedmaterial 130 and the lower horizontally formed and overlapped edges ofthese walls are provided with adhesively applied strips 132 of foamedmaterial. The arcuate slot 56 in the front wall 52 of the saw base ispreferably closed by a strip of foamed material (not shown) attached tothe wall 52 in a manner shown in FIGS. 5 and 6 of the drawings inapplicants' earlier application referred to herein above.

In FIG. 2 the remote end of hose 108 is shown connected to a source ofvacuum such as a conventional shop-vac 134. The saw guard 78 with thevacuum hose 108 connected thereto in the manner shown and described iseffective in the absence of such vacuum source in collecting table topsawdust due to airflow generated by the relatively rapid rotation of thesaw blade. When a vacuum source is not employed the remote end of thehose 108 may be connected to a suitable receptacle.

We claim:
 1. In a table saw having a horizontal worktable with front andrear sides, a circular saw blade mounted below the worktable and havinga peripheral portion thereof extending above the worktable rotatingtoward the front side of said worktable and a spreader having a portionextending above the rear side of the worktable; the improvement whichcomprises the provision and hinged attachment to said spreader portionof an elongated saw blade guard and table top sawdust collector havingrear and forward ends and extending between said rear and front sides ofsaid worktable and normally resting on said worktable and shrouding saidperipheral saw blade portion, said hinged attachment including an armpivotally connected at one end to said guard intermediately of itslength and pivotally connected at its other end to said spreader portionwhereby the forward end of said guard or said entire guard may beelevated above said worktable, said guard comprising a pair of verticalsidewalls having upper and lower horizontal edges and extending thelength of said guard, an inclined forward end wall and a horizontal topwall connecting said upper sidewall edge and extending from the rear endof said guard to a forward end spaced rearward from said forward endwall, a pair of sidewall portions extending upward from the upper edgesof said sidewalls and extending longitudinally from said forward end ofsaid top wall to said forward end wall, and a top wall portionconnecting the longitudinally extending upper edges of said sidewallportions whereby said top wall, said sidewall portions and said top wallportion defines a rearward facing opening, and a length of flexible hosehaving one end connected via a hose connected to a wall defining saidopening and said hose having an adjoining end portion extending rearwardand resting on and attached to said horizontal top wall.
 2. Theimprovement claimed in claim 1 in which said forward end wall extendsfrom said lower to upper edges of said sidewalls and is inclined forwardfrom said lower edge at an acute angle to the vertical, in which saidupper longitudinal edges of said sidewall portions and said top wallportion connecting them extend rearward and upward from the top of saidforward end wall at an acute angle to the horizontal, in which anarcuate depression having an axis parallel with said top wall portion isformed in said top wall at its forward end, a hollow cylindrical hoseconnector resting in said depression with its axis substantiallyparallel with said top wall portion and with the rearward end of saidtop wall portion extending into and lying contiguous with an internalsurface portion of said hose connector, and spring clip means detachablyconnecting said hose connector to said rear end of said top wallportion.
 3. The improvement claimed in claim 2 in which the spacing ofsaid sidewalls and said upwardly extending sidewall portions definingthe sides of said opening is substantially less than the inside diameterof said hollow cylindrical hose connector thereby providing apertures atopposite sides of said hose connector to permit substantial airflow intosaid hose connector from the exterior of said guard when a vacuum isapplied to said hose.
 4. The improvement claimed in claim 1 whichincludes a bracket for supporting an intermediate portion of said lengthof hose above said worktable, said bracket being generally L-shaped withthe end of its shorter, horizontal leg pivotally connected to a rearedge of said worktable below the upper surface thereof for rotation on ahorizontal axis and said leg being supported in a horizontal position ona support spaced horizontally from said pivotally connected end, thevertical longer leg of said bracket extending above said worktable andhaving an arcuate upper end for receiving and supporting said hose, andsaid horizontal leg being sufficiently flexible laterally to permitconvenient lateral displacement from said support member thereby topermit rotation of said entire bracket to a position below the uppersurface of said worktable.